IDENTIFICATION (with reason) OF Antedon sp. (B.Sc. ZOOLOGY_CCF-CC5_SEM4)

 Identifying features are:

1. Multicellular heterotroph.
2. embryonic development, preceded by heterogametic fertilization.

            Hence, the specimen belongs to the Kingdom Animalia.

1. Usually exhibit pentamerous symmetry.
2. Presence of external spines.
3. Oral surface directed downward.
4. Tube foot is present.
5. Five grooves named ambulacra are usually present.

           Hence, the specimen belongs to the Phylum Echinodermata

1. Stalked form.
2. Narrow & ciliated Ambulacral groove.
3. Tentacular tube feet are strongly ciliated.
4. Upwardly directed mouth.

             Hence, the specimen belongs to the Sub Phylum Crinozoa

1. Hemispherical body.
2. Branched arms five in number, bearing pinnules.
3. Anus is on the oral surface.
4. Ambulacral grooves are open.
5. Madreporite is absent.

            Hence, the specimen belongs to the Class Crinoidea

1. Body is largely composed of calyx covered by tegmen.
2. Anus is on a papilla in an inter radius.
3. Ten arms, long & slender radiated from central part of the body.
4. Leathery oral surface, with numerous calcareous  plates.
5. Ambulacral grooves divide into 10 & lead into arms.
6. Pinnule arises on alternate sides of each arm.

             Hence, the specimen seems to be Antedon sp.

Systematic Position (Ruppert & Barnes 1994)

 Kingdom: Animalia

   Phylum: Echinodermata

         Sub Phylum: Crinozoa

                 Class: Crinoidea

                     Genus: Antedon